用C#创建XML， XML格式化输出

demo:

XmlDocument doc = new XmlDocument();
XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", "GB2312", null);
doc.AppendChild(dec);
//创建一个根节点（一级）
XmlElement root = doc.CreateElement("First");
doc.AppendChild(root);
//创建节点（二级）
XmlNode node = doc.CreateElement("Seconde");
//创建节点（三级）
XmlElement element1 = doc.CreateElement("Third1");
element1.SetAttribute("Name", "Sam");
element1.SetAttribute("ID", "");
element1.InnerText = "Sam Comment";
node.AppendChild(element1);

XmlElement element2 = doc.CreateElement("Third2");
element2.SetAttribute("Name", "Round");
element2.SetAttribute("ID", "");
element2.InnerText = "Round Comment";
node.AppendChild(element2);

root.AppendChild(node);
doc.Save(@"d:\bb.xml");
Console.Write(doc.OuterXml);

格式化输出函数：

private static string formatXml(object xml){
    XmlDocument xd;
    if(xml is XmlDocument) {
        xd=xml as XmlDocument;
    }else{
        xd = new XmlDocument();
        xd.LoadXml(xml as string);
    }
    StringBuilder sb = new StringBuilder();
    StringWriter sw = new StringWriter(sb);
    XmlTextWriter xtw = null;
    try{
        xtw = new XmlTextWriter(sw);
        xtw.Formatting = Formatting.Indented;
        xtw.Indentation = ;
        xtw.IndentChar = '\t';
        xd.WriteTo(xtw);
    }finally{
        if (xtw != null)
            xtw.Close();
    }
    return sb.ToString();
}